Genetics Worksheets and Printables - Free Printable

Here is the step-by-step solution to the problems on the worksheet.

Part 1: Punnett Squares (Questions 1-3)

Question 1:
* The Cross: Parent 1 is `Hh` (H and h on the side) and Parent 2 is `hh` (h and h on the top).
* Filling the Square:
* Top-Left: `H` (from side) + `h` (from top) = Hh
* Top-Right: `H` (from side) + `h` (from top) = Hh
* Bottom-Left: `h` (from side) + `h` (from top) = hh
* Bottom-Right: `h` (from side) + `h` (from top) = hh
* Frequencies:
* HH: 0 (There are no HH boxes)
* Hh: 2 (Two boxes have Hh)
* hh: 2 (Two boxes have hh)
* Genotypes:
* P1: The parents are Hh and hh.
* F1: The offspring genotypes are Hh and hh.

Question 2:
* The Cross: Parent 1 is `AA` (A and A on the side) and Parent 2 is `aa` (a and a on the top).
* Filling the Square:
* Top-Left: `A` + `a` = Aa
* Top-Right: `A` + `a` = Aa
* Bottom-Left: `A` + `a` = Aa
* Bottom-Right: `A` + `a` = Aa
* Frequencies:
* AA: 0
* Aa: 4 (All four boxes are Aa)
* aa: 0
* Genotypes:
* P1: The parents are AA and aa.
* F1: The offspring genotype is Aa.

Question 3:
* The Cross: Parent 1 is `Bb` (B and b on the side) and Parent 2 is `Bb` (B and b on the top).
* Filling the Square:
* Top-Left: `B` + `B` = BB
* Top-Right: `B` + `b` = Bb
* Bottom-Left: `b` + `B` = Bb
* Bottom-Right: `b` + `b` = bb
* Frequencies:
* BB: 1
* Bb: 2
* bb: 1
* Genotypes:
* P1: The parents are Bb and Bb.
* F1: The offspring genotypes are BB, Bb, and bb.

---

Part 2: Monohybrid Cross Problems (Questions 4-5)

Question 4:
* The Problem: Tall (T) is dominant over dwarf (t). Cross a homozygous tall plant with a homozygous dwarf plant.
* Step 1: Determine Parent Genotypes (P1).
* Homozygous tall means two dominant alleles: TT.
* Homozygous dwarf means two recessive alleles: tt.
* Step 2: Set up the Cross.
* Cross: TT x tt
* Step 3: Fill the Punnett Square.
* All offspring will receive a `T` from the first parent and a `t` from the second parent.
* Result: Tt, Tt, Tt, Tt.
* Step 4: Determine F1 results.
* F1 Genotype(s): All are Tt.
* F1 Phenotype(s): Since T (tall) is dominant, all offspring will be Tall.

Question 5:
* The Problem: Cross two of the F1 generations from Question 4 (Tt x Tt).
* Step 1: Determine Parent Genotypes.
* Both parents are Tt.
* Step 2: Set up the Cross.
* Cross: Tt x Tt
* Step 3: Fill the Punnett Square.
* Top-Left: `T` + `T` = TT
* Top-Right: `T` + `t` = Tt
* Bottom-Left: `t` + `T` = Tt
* Bottom-Right: `t` + `t` = tt
* Step 4: Determine F2 results.
* F2 Genotype(s): We have TT, Tt, and tt.
* F2 Phenotype(s):
* TT is Tall.
* Tt is Tall.
* tt is Dwarf.
* So, the phenotypes are Tall and Dwarf.

Final Answer:
1. Punnett Square 1
* Frequencies: HH: 0, Hh: 2, hh: 2
* Genotypes: P1: Hh x hh, F1: Hh, hh

2. Punnett Square 2
* Frequencies: AA: 0, Aa: 4, aa: 0
* Genotypes: P1: AA x aa, F1: Aa

3. Punnett Square 3
* Frequencies: BB: 1, Bb: 2, bb: 1
* Genotypes: P1: Bb x Bb, F1: BB, Bb, bb

4. Monohybrid Cross Problem
* Cross: TT x tt
* P1 genotypes: TT, tt
* F1 genotype(s): Tt
* F1 phenotype(s): Tall

5. F1 Generation Cross
* Cross: Tt x Tt
* F1 genotypes: Tt
* F2 genotype(s): TT, Tt, tt
* F2 phenotype(s): Tall, Dwarf